The present invention is related to a micro-reflective liquid crystal display in which the color light-filtering plate is formed with an opening, whereby external light can go in through the opening. An upper metal layer of the storage capacitor serves to reflect the external light to serve as a light source for the liquid crystal display.
FIG. 4 shows a conventional Transmissive type Thin Film transistor (TFT) liquid crystal display. A liquid crystal layer 83 is disposed between the upper and lower substrates 81, 82. An upper polarizing plate 84 and a lower polarizing plate 85 are disposed respectively corresponding to the upper and lower substrates 81, 82. A backlight source (not shown) is disposed under the lower polarizing plate 85. A film transistor matrix electrode 86 and a storage capacitor 87 are disposed on the lower substrate 82 corresponding to each pixel. The storage capacitor 87 is composed of a lower metal layer 871, an insulating layer 872 and an upper metal layer 873 which are piled. A black matrix 88 is disposed under the upper substrate 81 corresponding to the thin film transistor matrix electrode 86 and a storage capacitor 87 to shade the same so as to avoid reduction of contrast of the displayed image.
The above TFT liquid crystal display lacks reflective structure for reflecting external light. Only the backlight source serves as the light source of the image. Therefore, when exposed to outdoor sunlight, the contrast of the image of the TFT liquid crystal display will be reduced so that the displayed image can be hardly clearly seen.
In order to obviate the above problem, some manufacturers arrange reflective board structure on the lower substrate corresponding to each pixel. The reflective board structure is composed of reflective electrode region and transparent electrode region. For example, such structure is disposed in Taiwanese Patent Publication No. 482917, entitled “liquid crystal display device” (U.S. Pat. No. 6,295,109). However, such structure will sacrifice the opening ratio of the transparent mode. Moreover, the manufacturing procedure is complicated and it is hard to design the optical structure.
In the existent micro-reflective liquid crystal display device, a dual brightness enhancement film (DBEF) with scattering particles is externally attached to the display for solving the problem of reduction of contrast. However, in reflective mode, the DBEF tends to result in parallax problem of the displayed image. In addition, the cost for the DBEF is quite high so that it is not economic to use the DBEF.